Lighting circuit breaker panelboard modular assembly including circuit breaker support mounting brackets

ABSTRACT

A circuit breaker panelboard modular assembly employs a plurality of interdependent molded plastic and metal parts to multifunctionally adapt breakers of different ratings for electrical connection within the panelboard enclosure. Anti-turn connector connects the line strap terminal. Captive bolts or plug-in connections are employed to attach the breakers to the power bus. A novel concealed hinge construction is used to connect the panelboard door to the panelboard housing and the breakers are individually identified within the housing by extruded plastic circuit markers.

This is a divisional of application Ser. No. 705,454, filed Feb. 25,1985, now U.S. Pat. No. 4,631,634.

BACKGROUND OF THE INVENTION

The increased use of computers throughout the circuit breaker industryfor inventory of circuit breaker components along with the automatedassembly of the components into a finished product has correspondinglyrequired a reduction in the large variety of components used with thevarious breaker ratings to make such automation practical as well aseconomically feasible. U.S. patent application Ser. No. 678,208 entitled"Automated Q-Line Circuit Breaker" in the name of Raymond Seymour et al.describes a 120/220 volt residential-type circuit breaker designed forcompletely automated assembly. U.S. patent application Ser. No. 500,643in the names of Ronald Ciarcia et al. entitled "Circuit Breaker DesignFor High Speed Assembly" describes a 277/480 volt circuit breakerdesigned for commercial applications, which is capable of automatedassembly, in part.

The industry trend toward the use of computerized inventory and partssimplification for circuit breaker manufacture implies that tremendoussavings in time and materials can also be realized in the manufacture ofthe panelboards and load centers used to house the residential andindustrial-type breakers. In the manufacture of industrial panelboards,for example, each breaker rating and design requires a tailoredpanelboard assembly for housing and supporting the breakers. Automationof industrial panelboard manufacture has heretofore been difficult toachieve because of the large variety of components required for thevarious breaker ratings. The use of sheet metal supports with insulatingplates as well as the large variety of screws, rivets and bolts requiredto assemble the metal panelboard internal assembly has complicatedearlier attempts to automatically assemble the panelboard enclosures.

The advent of high strength insulating plastic materials such as Noryl®and Valox® which are registered trademarks of General Electric Companyfor high temperature durable thermoplastic resins, has allowed the useof molded plastic components to multifunctionally provide the necessaryinsulation between the phase conductors as well as to space and supportthe breakers on the power buses.

One purpose of this invention is to describe an industrial circuitbreaker panelboard design wherein the panelboard components are capableof use with circuit breakers over a wide range of ratings withoutrequiring a correspondingly large variety of inventoried components andparts.

Another purpose of this invention is to propose a modular concept tocircuit breaker panelboard assembly wherein the main breaker, branchbreakers, neutral support and option support structures are configuredfor interconnection independent of length requirements. Any desirednumber of breakers can then be arranged on such a module and the moduleis then connected with the remaining modules of adjustableconfiguration. This modular concept can allow for a wide range ofcustomer requirements with only minor modification of the panelboardinterior.

SUMMARY OF THE INVENTION

The invention comprises an industrial circuit breaker panelboard designwherein molded plastic components are used to support and electricallyisolate the electric power bus phase conductors and to adapt variousbreaker ratings for electrical connection with each of the power buses.The use of main and branch circuit breaker modules allows a widevariation in the number of breakers that can be arranged within thepanelboard enclosure without modifying the panelboard interior. Anintegral panelboard door assembly containing a concealed durable hingeis used to simplify the external panelboard assembly. Anti-turnelectrical connectors are used to interconnect the circuit breakers withthe incoming electrical power conductors and captive bolts are used withthe breakers to connect the breakers to the power buses.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an end view in partial section of the panelboard modularassembly according to the invention;

FIG. 2 is a front view of the door assembly viewed from within thepanelboard assembly according to the invention;

FIG. 3 is top perspective view in isometric projection of the internalcomponents used within the panelboard assembly of FIG. 1;

FIG. 4 is a top perspective view in isometric projection of a circuitbreaker prior to connection with the interior components depicted inFIG. 2;

FIG. 4A is a partial end section through the plane A--A of the branchstrap adapter base depicted in FIG. 4;

FIG. 5 is a top perspective view of the anti-turn connectors used forconnecting the circuit breaker depicted in FIG. 3 with the electricalpower conductors;

FIG. 6 is top perspective view of an interior mounting bracket usedwithin the panelboard assembly of the instant invention;

FIG. 7 is a top perspective view of the interior mounting bracketconnecting with the interior of the panelboard assembly of the instantinvention;

FIGS. 8A-8C are top perspective views and side sectional views of thecircuit markers used within the panelboard assembly of the instantinvention FIG. 8B is a section through the plane 8B--8B and FIG. 8C is asection through the plane 8C--8C of the circuit markers as depicted inFIG. 8A;

FIG. 9 is an enlarged top perspective view in isometric projection ofthe novel hinge arrangement used with the panelboard door assemblydepicted in FIG. 1; and

FIG. 10 is a top perspective view of an alternate embodiment of thepanelboard assembly according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The lighting circuit breaker panelboard modular assembly of theinvention is shown at 10 in FIG. 1 to consist of an enclosure bounded onboth sides by a pair of opposing sidewalls 6 and a bottom pan 8. A doorassembly 114 is arranged at the front of the assembly and consists of aface plate 11 which can be made of plastic or metal and which surroundsthe door 12. A rabbet 14 surrounds the interior of the door assembly toprovide a barrier in combination with the circuit breaker shield 48 alsomade of plastic or metal, which is positioned within the panelboardassembly by means of a pair of shield supports 17. Although not shown,the circuit breakers are arranged on top of a base 32 by means of thecircuit breaker support hooks 34 and insulators 33 integrally formedwithin the base. The base is injection molded from Noryl plastic whichwas selected for its strength and good electrical resistance properties.Electrical connection is made with the power buses 30 which are attachedto the bottom portion of the base. Each power bus carries one phase of asingle or three phase power supply. The base is supported by means of apair of side rails 26 which in turn are supported by a pan 112. A hinge15 is arranged on the interior of the face plate and door in such amanner as to be completely concealed from the exterior of the door asseen by referring now to FIG. 2

FIG. 2 depicts the door assembly 114 as viewed from the interior of thepanelboard assembly wherein the hinges 15 are shown attached between thedoor 12 and the rabbet 14 within a hinge opening 1 formed within therabbet 14. A clearance gap 110 is provided between the door and the faceplate, and the handle opening 13 is formed within the door to allow forthe attachment of an operating handle and lock (not shown).

FIG. 3 shows the interior components prior to attachment within thepanelboard assembly. A main circuit breaker module 19 is comprised of apan 16 having L-shaped extensions 9 containing a plurality of holes 18to facilitate attachment of the pan to the interior of the assembly. Aninsulating barrier 23 separated from the pan 16 by means of legs 24 isused to electrically isolate the circuit breaker connecting straps 21 bymeans of spaced insulating shields 138. Electrical connection is madebetween the bus bars 30 and the connecting straps 21 by means of threecopper straps 130 and terminal screws 22, although only one is shown forpurposes of clarity. A main circuit breaker 20 or a main wire terminallug such as depicted at 77 in FIG. 10 is carried by the main circuitbreaker module and a pair of upright shield supports 17 are provided oneach of the L-shaped extensions 9 at one end of the module to support apair of shield rails 44 at that end. A branch circuit breaker module 25is shown to consist of a pair of opposing side rails 26 connectedtogether by means of a pair of crossbars 27 which support and attach tothe busbars 30 by means of bolts extending downward through therespective bolt recesses 29 formed in the cross bars and the bus holes35 which extend along each of the buses, as indicated. A pair ofcrossbar side rails 28 are formed within the crossbars to provideadditional support strength. The base 32 is supported both by thebusbars as well as by the side rails and serves to support a number ofbranch circuit breakers 31 which are removably mounted on the circuitbreaker support hooks 34 formed within the base 32 and separated byinsulators. The neutral connection module 36 includes a neutral base 37made of sheet metal which supports a pair of shield supports 17 at oneend to which the opposite end of the pair of shield rails 44 areattached. The large number of holes 45 provided within the shield railsallows the shield supports 17 to be fastened at any desired location.The neutral connection module 36 further comprises a pair of opposingangle supports 39 of an insulating material on which a metal platform 38is placed. A plurality of neutral connectors 42 are mounted at one sideof the platform and a neutral lug 40 is fastened to the platformproximate the neutral connectors by means of a screw 41. The maincircuit breaker module 19, branch circuit breaker module 25, and neutralconnection module 36 are mechanically interconnected by overlaying anend portion of the branch circuit breaker module side rails 26 on an endportion of the main circuit breaker module side rail L-shaped extensions9 and inserting at least two bolts on each side of the modules throughthe corresponding screw holes 18 and by overlaying an opposite endportion of the branch breaker module side rails 26 on an end portion ofthe neutral connection module side rails 131 and inserting at least twobolts on each side of the module through the corresponding screw holes18. The variability in the length of the individual side rails for eachindividual module is an important feature of the instant invention.Earlier panelboard side rail length configurations generally fixed thepanelboard interior dimensions and thereby limited the flexibility ofthe design. The arrangement of each individual pair of side rails foreach individual module now allows a large amount of flexibility within afixed panelboard length. Each module now is assigned one of theaforementioned functions, such as main breaker or branch breaker supportfor example, and the individual module lengths can be varied by simplyadjusting the length of the respective side rails. Electrical connectionis made with the neutral connection module by means of a plurality ofneutral terminals 43 while electrical connection between the neutralconnectors 42, neutral lug 40 and neutral terminals 43 is made by meansof the metal platform 38. The main and branch circuit breaker modulesare electrically interconnected by attaching the ends of the busbars 30on the branch circuit breaker module 25 to the circuit breakerconnection straps 21 by means of the terminal screws 22 and copperstraps 130 as described earlier. The neutral connection module 36 isthen abutted against the opposite end of the branch circuit breakermodule 25. Once the individual modules are interconnected and the pairof shield rails 44 are attached, the subassembly is then arranged withinthe bottom pan 8 which consists of the opposing sidewalls 6 and theopposing end walls 5. A plurality of mounting holes 7 are arranged onthe bottom of the bottom pan 8 to facilitate attachment within the fieldbefore the subassembly is inserted therein. A main circuit breakershield 46 having a handle opening 47, for providing operative access tothe main circuit breaker, and a top shield 139 are supported between theshield rails 44 along with a branch breaker shield 48 which contains ashield shelf 4 along both sides of the shield and a pair of breakeraccess openings 49 through which the top of the branch breakers 31extend. A neutral shield 140 is also supported between the same shieldrails to completely shield the interior assembly.

When a larger-rated branch circuit breaker is to be used within thebranch circuit breaker module 25, the branch strap adapter 53 shown inFIG. 4 is used in place of the base 32 depicted earlier in FIGS. 1 and3. The branch strap adapter is indicated in phantom in FIG. 1 to showits arrangement within the interior of the panelboard assembly 10. Thebranch strap adapter consists of a cover 57 and a base 54 both made ofNoryl. The cover has a tube 63 integrally formed therein with an opening64 defined for receiving a sleeve 65 arranged at one end of the branchbreaker 31. Electrical connection is made between the branch breaker andone of the power buses 30 by fastening the captive screws 66 whichextend through the circuit breaker terminal straps 67, sleeve 65 andtube 63 to a hole 69 tapped within the branch strap 68. A threaded bolt70 is then inserted through the oblong hole 71 within the cover 57, andthrough the oblong hole 116 within an offset 115 formed at one end ofthe branch strap 68, where it is securely fastened to one of the powerbuses 30 within the bus hole 35 through the opening 129 formed in thebottom 113. Although only one branch strap adapter 53 is shown, thereare three such adapters employed, one for each of the three power buses30. When the branch circuit breaker is to be connected with theappropriate power bus 30 by means of the branch strap adapter 53, thecover 57 is first attached to the base 54 by fitting the edges of thecover within the linear passage 59, 60 defined between the outer wallsof the base and the inner formed rectangle 58 as shown. Upon insertionof the edges of the cover 57 within the linear passage, four protrusions62 formed on the outside of the edges of the cover become captured byfour corresponding slots 61 formed in the sides of the base 54. Thebottom 113 of the base 54 insulates the branch strap 68 from the otherbusbars which are not connected with the branch strap while providingaccess to one of the underlying bus bars 30 by means of the opening 129.A pair of unique busbar locating holes 117, extending through the branchstrap 68, and posts 118, formed on the bottom 113, ensure the correctline-up between the circuit breaker captive screw 66 and the hole 69within the branch strap 68 as well as between the slotted hole 116within the branch strap and the underlying busbar hole 35. A circuitbreaker support bracket 72 is attached to the base 54 by means of ascrew 76 and a screw hole 121 formed in the base. Attachment between thebranch breaker and the support bracket is made by means of a long screw73 which extends through the circuit breaker mounting hole 74 and a hole75 tapped within the support bracket 72. The assembled branch strapadapter 53 is attached to the side rails 26 by means of a pair of clamps50 at each end of the adapter which attach to the side rails by means ofbolts 51 and engage the recessed ends 55, 56 of the base by means ofhooks 52. The operation of the busbar locating holes 117 and posts 118is best seen by referring now to FIG. 4A. The branch strap 68 has eithera narrow busbar locating hole 117 for connecting with a narrow busbar ora wide locating hole 117' for connecting with a wider busbar extendingcompletely through it. The busbar locating post 118 seats the bottom ofthe narrow branch strap hole 117 on a narrow shoulder 119 as indicatedin solid lines and seats the bottom of the wide branch strap hole 117'on a wide shoulder 120 as indicated in phantom. The linear passages 59,60 are seen to extend along both sides of the base 54 as indicated and ahollow cylinder 126 integrally formed within the bottom 113 of the base54 is located between the busbar locating posts 118. The purpose of thecylinder 126, which is closed at the bottom as indicated at 127, is toallow for the clearance of the bottom shank of the circuit breakercaptive screw 66 and to insulate the screw from the interior of thepanelboard assembly.

Electrical connection between the busbars 30 with other electricalcomponents is made by means of the anti-turn connector 80 shown in FIG.5 which is first connected to the busbar 30 by means of a pair of screws91, passing through a pair of screw holes 90 formed within theconnector, to a corresponding pair of screw holes 35 formed within thebusbar. A bolt 85 having a hex head 84 and a formed washer 86 fixedlyattached to the head is inserted within a hexagonal slot 82 formedwithin a recess 83 within the connector. The bolt is retained frompassing through the hex slot by the engagement of the formed washer 86within the recess 83. The busbar 30 is positioned such that the bolt 85extends through the busbar hole 35 and through a corresponding hole 87formed within a step 88 extending from the wire terminal lug 77. The hexnut 89 is threadingly attached to the bolt 85 and a conductor (notshown) is inserted within the opening 78 defined within the wireterminal lug before the screw 79 is employed to fasten the conductorwithin the lug.

In some lighting power distribution circuits, the main circuit breakeris not used and the branch circuit breaker then connects with the powercircuit by means of three wire terminal lugs 77 as shown in both FIGS. 5and 10. Although three phase power circuits, which require three wireterminal lugs are disclosed, this is by way of example only. It is wellunderstood that in single phase power circuits, only two power buses arerequired and only two such wire terminal lugs would be employed. Theneutral connection module is not generally used with this circuitarrangement and a split neutral assembly module 132 is used in itsplace. The branch circuit breaker module 25 shown in FIG. 10 is similarto that depicted in FIG. 3 and like reference numerals will be employedfor similar components. The branch circuit breakers 31 are mounted on abase 32 and the busbars 30 are attached to the crossbars with side rails26 running parallel to the bus bars. Instead of connecting the bus barsto a main breaker, three wire terminal lugs 77 are connected with themain conductor (not shown) and with the bus bars 30 in the mannerdepicted in FIG. 5. The ends of the bus bars are arranged between thelug connectors and corresponding anti-turn connectors 80 and areattached to the anti-turn connectors by means of bolts 91 which extendthrough bolt holes 90 on the anti-turn connector and are engaged withinbolt holes 35 within the bus bars. The anti-turn connector 80 isconnected with both the bus bars 30 and the wire terminal lugs by meansof the bolt 85 and the hex nut 89 as described earlier. Referring againto FIG. 10, only one wire terminal lug 77 is indicated beforeattachment, with the other two lugs and anti-turn connectors alreadyattached. Once the wire terminal lugs are attached to the branch circuitbreaker module, the split neutral module is attached by placing aportion of the ends of the branch circuit breaker module side rails 26over a portion of the split neutral module side rails and joining themodules by means of at least two bolts through the respective side railbolt holes 18. When the modules are thus fastened together, the wireterminal lugs sit within the insulating barrier 23 and are insulatedfrom each other by means of the insulating shields 138 and from the pan16 by means of the legs 24. Neutral connections are made with the splitneutral assembly module 132 by means of the split neutral assembly 133which basically consists of a pair of insulating terminal bases 134joined by means of a connecting strap 137. Individual circuitconnections are made by means of a plurality of terminal connectors 135arranged on both of the terminal bases. Once the two modules areattached together, a modified main breaker shield similar to that shownin FIG. 3, without the handle opening 47, is attached by means of theshield rails 44 and shield supports 17 to the split neutral assemblymodule 132. The branch breaker shield 48, also shown in FIG. 3, isconnected to the branch circuit breaker module 25 by means of the shieldrail and shield supports to complete the assembly.

The attachment between the side rails 26, and the bottom pan 8 is madeby means of a plurality of bolts 100, 101 and angulated mountingbrackets 92 best seen by referring to FIGS. 3, 6 and 7. The angulatedmounting bracket 92 is shown in FIG. 6 to comprise a top step 94 and abottom step 95 offset in opposite directions from a vertical riser 93.The bracket is formed from a single piece of metal and a keyhole-shapedslot 98 is formed in the top step along with several holes 96. A similarkeyhole-shaped slot 99 is formed in the bottom step along with aplurality of holes 97 that receive bolts 100. The keyhole-shaped top andbottom slots comprise dual diameter openings with the smaller diameterof one of the slots facing in an opposite direction from the other slot.This allows the angulated mounting bracket to be used in any orientationwithout having to use four separate mounting brackets oriented in fourseparated directions since it is desirable to provide the dual diameterslot configuration for ease in attachment of the bolt 101 indicated inFIG. 7 for attachment within a screw hole 7 arranged within the bottompan 8. The provision of the angulated mounting brackets 92 assure thatthe bases 32 are provided with sufficient support and that the crossbars 27 are firmly supported within the panelboard assembly. Furthersupport is provided to the cross bars 27 by means of a plurality of ribs122 formed during the molding process. Prior art side rails were fixedlyattached to the bottom on only the ends of the side rails since the siderail length was a constant dimension. The provision of several mountingbrackets having side rail receiving holes 96, 97 and bottom panreceiving keyhole shaped slots 98, 99 now allows the module side railsto be attached at any desired location along the side rails 26.

FIG. 8A shows a plurality of branch breakers 31 attached within thepanelboard assembly and each containing a circuit marker 102 containingidentifying indicia 103 in the form of numbers identifying eachparticular branch breaker with a particular circuit. After the circuitbreakers are connected either by means of a base 32 such a describedearlier with reference to FIG. 3, or by means of the branch strapadapter 53 described earlier with reference to FIG. 4, the branchbreaker shield 48 best seen in FIG. 3 is placed over the breakers bymounting the shield platforms 128 on the shield rails 44 which werepreviously attached to the assembly by means of shield supports 17. Thecircuit markers 102 are attached to the shield shelf 4 prior to placingthe shield over the branch breakers. The circuit marker 102 as detailedin FIGS. 8B and 8C consists of a U-shaped clip configuration made of adurable plastic material and defining a bight portion 123 with a pair oflegs 124, 125 formed such that the legs toe in towards each other tofirmly hold the circuit marker to the shield shelf 4. To prevent thecircuit markers from sliding along the shelf, a plurality of dimples 105are formed along the shelf extent such that a downward protrusion 106,best seen in FIG. 8B, prevents each of the circuit markers 102 frommoving along the shelf. A matte surface 104 is formed on the circuitmarker by abrasion or otherwise roughening the plastic surface so that aball point pen or pencil can be used to write the description of theappliances or lighting fixtures which are protected by the indicatedbranch breaker.

The integrally formed hinges 15 shown attached to the inner surface ofboth the face plate 11 and the door 12 are attached to the door and faceplate by the assembly depicted in FIG. 9. The door 12 is initially cutfrom a single sheet of steel defining a clearance gap 110 between theface plate 11 and the door 12 as indicated. The hinge 15 is formed froma single sheet of steel and defines a formed circular end 109 and anL-shaped end 111 as indicated. The flat portion IIIA of the L-shaped endis robotically welded to the door 12 and a pin 108 is inserted withinthe formed circular end 109. A rabbet 14 formed from a single steelplate bent at right angles to provide a telescoping extension 2 alongits entire length is used to hold the hinge 15 between the face plateand the door. The rabbet has a hinge opening 1 cut in the vicinity ofthe hinges proximate the top and bottom of the door and a pair of formedsemi-circular protrusions 107, which correspond to and capture the pins108, when the rabbet is robotically spot-welded to the face plate 11 andthe hinge 15 protrudes upwards through the hinge opening 1. When therabbet is welded to the face plate, the door can freely open by theclearance provided the hinge through the hinge opening 1 and pins 108can rotate within the formed circular protrusions 107. It is noted thatwith the door 12 both in its open and closed positions, the formed hinge15 is completely inaccessible from the front surface of the panelboardassembly.

A review of the drawing figures indicates that all the installment stepsfor the panelboard assembly components can be made in a "downward"motion which is intended for purposes of automated assembly. Theinterrelationship between the component parts is such that roboticinstallation of the components can be made as the parts proceed along aconveyor with each of the components arrayed along the conveyor for bothinstallation and testing at each robot position.

Having described our invention, what we claim as new and desire tosecure by Letters Patent is:
 1. A circuit breaker panelboard assemblycomprising:closure means comprising opposing side walls and opposing endwalls joined by a bottom housing at least one main circuit breaker or atleast one main wire terminal lug and a plurality of branch circuitbreakers; access means movably arranged on said closure means providingaccess to said main and said branch circuit breakers from outside ofsaid closure means; circuit breaker mounting means within said closuresupporting said branch circuit breakers and providing electricalconnection between said branch circuit breakers and electrical bus barsconnectable with an external circuit; shield means intermediate saidaccess means and said main and branch circuit breakers preventingcontact with electrical terminals on said main and branch circuitbreakers; and a pair of angulated brackets attached at one end to saidbottom and at an opposite end to a corresponding pair of mounting rails,said circuit breaker mounting means being arranged across said pair ofmounting rails; said angulated brackets each comprising a metal plateformed into a top and a bottom step offset from a vertical riser, saidtop and bottom steps each containing a keyhole shaped opening and aplurality of bolt access openings, said top and bottom keyhole shapedopenings each facing in opposite directions and each defining a largeand small diameter passage; whereby the small diameter passage on saidbottom keyhole shaped opening is opposite in direction from said smalldiameter passage on said top keyhole shaped opening.
 2. The circuitbreaker panelboard assembly of claim 1 wherein each of said branchcircuit breakers carries three terminal connections attached to one endof each breaker for electrical connection with said bus bars, and acaptive screw arranged through each of said terminal connections andthrough corresponding tubular sleeves, said tubular sleeves beingadapted for ease in connecting said terminal connections with said busbars.